1. Field of the Invention
The present invention relates to an apparatus, system, and method of inspecting an image formed by an image forming apparatus, and a recording medium storing an image inspection control program.
2. Description of the Related Art
Conventionally, the inspection of printed matter has been performed by human operators. In recent years, inspection apparatuses that automatically inspect printed matter have been widely used, mainly in the field of offset printing. For example, in conventional devices a master image would be generated by reading specific printed matter that was selected based on the image quality, as a reference image. The corresponding portions of the master image and a subsequently read image of printed matter would be compared to determine, by the degree of difference therebetween, whether there was a defect in the printed matter.
Printing apparatuses, such as electrophotographic apparatuses, have been widely used to print a small number of pages. For example, a printing apparatus may perform variable printing in which the printed contents differ on each page. In such case, comparing the printed matter, with a master image generated from previously printed matter, would be inefficient. In view of this, the master image has typically been generated based on print data and then compared with the printed image to be inspected.
Japanese Patent Application Publication No. 2005-217931-A proposes a method of performing quality determination with a threshold higher in a specific area than in other areas outside the specific area.
In particular, this publication describes executing a defect determination of printed matter based on a defect level indicating the degree of the defect for each type of defect. The types of defect include faint printing, dirty marks, and excess lines. In this publication, an image inspection apparatus is used to determine whether there is a defect in the printed matter based on the degree of difference between corresponding portions of the master image and a read printed matter image. Further, the image inspection apparatus identifies the type of defect and the defect level from the printed matter image.
The image inspection apparatus then determines whether the identified defect level for each type of defect exceeds a permissible defect level for each type of defect. When the identified defect level for each type of defect exceeds the permissible defect level, the image inspection apparatus determines that the printed matter is abnormal. In the above noted system the user must manually set the permissible defect level for each type of defect. However, it is difficult for the user to intuitively set the permissible defect level for each type of defect. Furthermore, the technology disclosed by JP-2005-217931-A only performs a quality determination in a specific area and does not set the permissible defect level for each type of defect. As a result, the permissible defect level automatically set for the specific area is not always the level desired by the user.
In view of the above, the inventors of the present embodiments have discovered that there is a need for an apparatus, a system, a method, and a non-transitory recording medium storing an image inspection control program, each of which is capable of permitting the user to intuitively set the permissible defect level for each type of defect.